Optically transparent polymeric solid electrolyte

Abstract

Optically transparent polymeric solid electrolytes comprising a polymeric binder, a filler, a conductive salt, an ion-solvating plasticizer and, if desired, further additives and auxiliaries, a process for the preparation of solid electrolytes of this type, by compounding and thermoplastic shaping, and their use in electrochromic systems and displays.

We claim:  
     
       1. An optically transparent polymeric solid electrolyte having a light transparency of >80% and a conductivity of greater than 10 −6  S/cm at 20° C., comprising 
       at least one polymeric binder having a glass transition temperature of T g  of <−30° C.,  
       at least one filler having a primary particle size of from 1 nm to 20 μm,  
       at least one conductive salt,  
       at least one ion-solvating plasticizer, and  
       optionally, further additives and auxiliaries.  
     
     
       2. A solid electrolyte as claimed in  claim 1 , wherein the filler is an inorganic filler having a primary particle size of from 1 nm to 300 nm. 
     
     
       3. A film consisting of a solid electrolyte as claimed in  claim 1 . 
     
     
       4. A solid electrolyte film as claimed in  claim 3 , wherein the solid electrolyte is in a crosslinked form. 
     
     
       5. A process for the production of an optically transparent polymeric solid electrolyte film having a light transparency of >80%, a conductivity of greater than 10 −6  S/cm at 20° C. and a glass transition temperature T g  of <−30° C., which comprises mixing 
       at least one polymeric binder,  
       at least one filler having a primary particle size of from 1 nm to 20 μm,  
       at least one conductive salt,  
       at least one ion-solvating plasticizer, and  
       optionally, further additives and auxiliaries, intensively with one another and thermoplastically shaping the mixture to give a film.  
     
     
       6. A process as claimed in  claim 5 , wherein the film is crosslinked photochemically, thermally or by electron radiation. 
     
     
       7. In an electrochromic glazing system, in which the light transparency can be adjusted reversibly and steplessly, which comprises a first glass sheet, a first transparent electroconductive layer, an electrochromic electrode, an electrolyte, a counterelectrode, a second transparent electroconductive layer and a second glass sheet, the improvement comprising the presence of the optically transparent polymeric solid electrolyte of  claim 1  as said electrolyte.